Device for transmission of forces in a flexible sheath



1965 M. MARTINOT 3,217,557

DEVICE FOR TRANSMISSION OF FORCES IN A FLEXIBLE SHEATH Filed Dec. 10, 1962 United States Patent 3,217,557 DEVICE FOR TRANSMISSION 0F FURCES IN A FLEXIBLE SHEATH Maxime Martinot, 110 Ave. Anatole France, Vitry=snr-Seine, Seine, France Filed Dec. 10, 1962, Scr. No. 243,675 Claims priority, applicaiior; France, Dec. 9, 1961, 88 ,5 1 2 Claims. (Cl. 74-501) The present invention relates to devices which allow compression or tension forces to be transmitted over a substantial distance, and which have a relatively flexible, rectilinear or bent sheath.

It is an object of the invention to make a device of this nature which is light, inexpensive and flexible.

With this and other objects in view, the invention provides a device for transmitting a force, comprising a tubular sheath, a relatively flexible rod-like member freely movable along the longitudinal axis of said sheath, fixed guiding tracks located within and secured to said sheath, and a plurality of ball-bearings located between said rodlike member and said gniiding tracks, said guiding tracks being formed as cages for said ball-bearings and having stop members to limit the longitudinal movement of said ball-bearings.

Thus, when the rod-like member moves, the ball-bearings roll freely between the stops, the distance travelled by the ball-bearings being equal to half that travelled by the said member.

In order that the invention may be more clearly understood, reference will be made to the accompanying drawing which shows one embodiment thereof by Way of a non-limiting example and in which:

FIGURE 1 shows a perspective view of a device to which the invention relates, the outer sheath thereof being partially cut away, and FIGURE 2 shows a cross section of the device of FIGURE 1, but omitting the sheath entirely.

Referring to the drawings, there is shown a device which comprises a tubular sheath 1, made of a relatively flexible material such as a plastic material and two guiding tracks 2 and 3 fixed to the said sheath.

A mobile rod-like member 4 is located along the longitudinal axis of the sheath 1, and is made free to move longitudinally without friction by the provision of ballbearings 5 on both sides of the member 4, between the latter and the guiding tracks 2 and 3.

In accordance with the invention, the guiding tracks 2 and 3 also form cages for the ball-bearings 5 in that they are provided at regular intervals with indentations at 2a and 3a, forming stops to limit the longitudinal movement of the ball-bearings.

When the rod-like member 4 moves, the ball-bearings roll freely between two consecutive indentations forming stops, the distance travelled by the ball-bearings being equal to half that travelled by the rod.

In the device according to the invention, it is no longer necessary, as was hitherto the case, to provide independent cages for the ball-bearings and the latter are no longer hindered in their rotation, as often occurred.

3,217,557 Patented Nov. 16, 1965 Further, besides the economy resulting from the omlssion of the independent cages, the device is lighter and more flexible.

The invention is not limited to the embodiment described and illustrated above, but, on the contrary, covers all variations of construction and application. In particular, the stops formed on the guiding tracks themselves may be made in quite a diiferent manner from the mdentations described above. For example, they can be separate devices clipped in place to the edges of the tracks 2 and 3.

What I claim is:

1. A device for transmitting a force, comprising:

(a) a flexible tubular sheath;

(b) a relatively flexible, flat rod-like member freely movable along the longitudinal axis of said sheath;

(0) said member having a pair of parallel, oppositely directed faces each of which has a longitudinal groove therein;

(d) a pair of fixed guiding tracks extending longitudinally within and secured to said sheath with said member located between said tracks;

(e) a plurality of pairs of ball-bearings of uniform size spaced longitudinally along the interior of said sheath;

(f) with one ball-bearing of each of said pair-s being disposed between one of said guiding tracks and the groove in one of said parallel faces of said rod-like member, and the other ball-bearing of each of said pairs being disposed between the other of said guiding tracks and the groove in the other of said faces of said member;

(g) the inner longitudinal surfaces of said guiding tracks and said grooves in the parallel faces of said rod-like member having transverse cross-sections each of which is in the form of a circular arc having a radius of curvature equal to that of each of said ballbearings, to form cages for said ball-bearings; and

(h) said guiding tracks having parts thereof forming stop members disposed along the opposite sides of each track on planes perpendicular to the longitudinal axes of said tracks so as to extend radially inward of said transverse cross-sections of said inner longitudinal surfaces of said guiding tracks, said stop members serving to limit the longitudinal movement of said ball-bearings therealong. 2. A device as in claim 1; wherein said stop members of said guiding tracks are disposed in transversely aligned pairs along the length of each of said tracks.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,239 9/1862 Pearlstine 308-6 X 846,079 3/1907 Yost 642 1,151,898 8/1915 Neal 3086 2,261,504 11/1941 Saunders 308-38 2,845,813 8/1958 Richoux 74-501 2,987,348 6/1961 Blazek 3086 3,055,714 9/1962 Coflin 3086 BROUGHTON G. DURHAM, Primary Examiner. ROBERT C. RIORDON, Examiner. 

1. A DEVICE FOR TRANSMITTING A FORCE, COMPRISING: (A) A FLEXIBLE TUBULR SHEATH; (B) A RELATIVELY FLEXIBLE, FLAT ROD-LIKE MEMBER FREELY MOVABLE ALONG THE LONGITUDINAL AXIS OF SAID SHEATH; (C) SAID MEMBER HAING A PAIR OF PARALLEL, OPPOSITELY DIRECTED FACES EACH OF WHICH HAS A LONGITUDINAL GROOVE THEREIN; (D) A PAIR OF FIXED GUIDING TRACKS EXTENDING LONGITUDINALLY WITHIN AND SECURED TO SAID SHEATH WITH SAID MEMBER LOCATED BETWEEN SAID TRACKS; (E) A PLURALITY OF PAIRS OF BALL-BEARINGS OF UNIFORM SIZE SPACED LONGITUDINALLY ALONG THE INTERIOR OF SAID SHEATH; (F) WITH ONE BALL-BEARING OF EACH OF SAID PAIRS BEING DISPOSED BETWEEN ONE OF SAID GUIDING TRACKS AND THE GROOVE IN ONE OF SAID PARALLEL FACES OF SAID ROD-LIKE MEMBER, AND THE OTHER BALL-BEARING OF EACH OF SIAD PAIRS BEING DISPOSED BETWEEN THE OTHER OF SAID GUIDING TRACKS AND THE GROOVE IN THE OTHER OF SAID FACES OF SAID MEMBER; 